Field
Aspects of the present invention generally relate to a method for generating image data through a plurality of generation units.
Description of the Related Art
At present, full high-definition (HD) (1920×1080) is generally employed as definition of digital televisions. However, standardization of image data at higher-definition such as 4K2K (4096×2160) and super hi-vision (or ultra-high definition) (7680×4320) is in progress, so that devices capable of displaying these high-definition image data are now being provided.
In order to execute various processing of the high-definition image data such as receiving processing, image processing, and output processing to display devices, an image input-output interface and a memory interface having wider band are necessary. Further, there may be a case where the above processing cannot be executed by a single image processing large-scale integration (LSI) chip because a calculation amount thereof has been increased. Therefore, in order to execute the receiving processing, the image processing, and the output processing of the high-definition image data, there is provided a method in which the image processing is executed in a unit of divided image data by spatially dividing the high-definition image data. For example, by dividing the high-definition image data into a right-half and a left-half portion, the image processing of the divided portions of image data may be concurrently executed by two image processing LSI chips.
In addition, the image processing LSI chip executes the processing other than the image data processing. In other words, the image processing LSI chip also includes a function of generating graphic data such as information relating to displayed image data, a setting menu, a Web screen, or a photograph and outputting the image data by superimposing the graphic data on the image data. Because higher definition is employed for the image data, definition of the graphic data to be superimposed thereon is also higher, and thus the calculation amount of the graphic data generation processing is increased. Therefore, in a same manner as the image processing of the high-definition image data, the graphic data is also generated by using graphic generation units included in a plurality of the image processing LSI chips.
Japanese Patent Application Laid-Open No. 2010-162745 discusses a technique for improving the speed of distributed processing. In the technique, processing is distributed to a plurality of processing units to make respective processing loads uniform by estimating the processing load for the image formation of the graphic data that is divided into rectangular-shaped image blocks.
However, differently from the high-definition image data, a display region of the graphic data to be superimposed may not be constant. In other words, the graphic data may be displayed on the entire region, displayed mainly on a left-half region, or displayed only on the left-half region. Furthermore, the processing load of the graphic data generation is not constant in the entire region of the graphic data. For example, in a case where the graphic data includes a region configured of complex image data such as a photograph and a region simply configured of text data, the processing load of the graphic data generation is larger in the region configured of the image data than in the region configured of the text data. Therefore, if the graphic data generation processing is distributed according to a boundary between divided regions of the high-definition image data, the processing load thereof may be concentrated in a graphic generation unit of one image processing chip. In such a case, even though a plurality of graphic generation units is employed therefor, the processing loads thereof cannot be uniform, and thus efficiency of generating the graphic data will be reduced. This may result in reduction of graphic data display speed.
Further, with the configuration discussed in Japanese Patent Application Laid-Open No. 2010-162745, processing for estimating the processing load of the graphic data will be necessary. Furthermore, with the technique discussed in Japanese Patent Application Laid-Open No. 2010-162745, in addition to a result of the above estimation, it is necessary to allocate the graphic data generation processing while taking a display region of the graphic data into consideration. Accordingly, the processing load for determining the allocation of the graphic data generation processing is increased, thus the display speed of the graphic data is reduced.